Materials / Compare
Plastic PEEK vs. Plastic TPU
Compare Plastic PEEK vs. Plastic TPU strength, stiffness, weight and thermal properties.
| Try it on a partA bracket to run stress or thermal on, free in your browser | Open in LessCAD | Open in LessCAD |
|---|---|---|
| Mechanical | ||
| Yield strength | 98MPasourcetypical, tensile yield | not given (tensile used) |
| Ultimate tensile strength | not sourced | 23.7MPasourcetypical, stress at break |
| Compressive strength | 125MPasourcetypical, 23 C | not sourced |
| Flexural strength | 165MPasourcetypical, flexural stress at yield, 23 C | 4.1MPasourcetypical |
| Elongation at break | 25%sourcetypical, at break | not sourced |
| Young's modulus (stiffness) | 4GPasourcetypical (nominal) | 0.067GPasourcetypical |
| Density | 1,300kg/m³sourcetypical (crystalline) | 1,220kg/m³sourcetypical |
| Strength to weight | 75.4kN·m/kg3.88x higher | 19.4kN·m/kg |
| Stiffness to weight | 3.08MN·m/kg56x higher | 0.0549MN·m/kg |
| Poisson's ratio | 0.38sourcetypical | not sourced |
| Shear modulus | 1.45GPa | not sourced |
| Bulk modulus | 5.56GPa | not sourced |
| Speed of sound | 1,754m/s | 234m/s |
| Thermal | ||
| Thermal conductivity | 0.29W/m·Ksourcetypical, average, 23 C | not sourced |
| Thermal expansion | 55µm/m·Ksourceaverage of flow/cross-flow, below Tg (<143 C) | not sourced |
| 100 mm part over a 50 °C swing | 275µm growth | not sourced |
| Specific heat | 2,200J/kg·Ksourcetypical, 23 °C, DSC (Victrex PEEK 450G TDS, revision Jul 2012) | not sourced |
| Heats up and cools (diffusivity) | 0.101mm²/s | not sourced |
| Thermal shock resistance | 80.1W/m | not sourced |
| Melting point | 343°Csourcetypical, DSC | 217°Csourcetypical |
| Glass transition | 143°Csourceonset (midpoint 150 C) | not sourced |
| Max service temperature | 240°CsourceUL 746B RTI, mechanical strength (continuous use index) | 50.3°CsourceHDT 0.455 MPa (printed specimens) |
| Values for | Victrex PEEK 450G (unreinforced, injection moulded), Victrex TDS rev. March 2026; Poisson from Victrex fluid-management flyer (2020-07) | Ultimaker TPU 95A, 3D-printed specimens, XY (flat); Ultimaker S5 Pro, engineering intent profile, 0.15 mm layer height, AA 0.4 print core, 100% infill, Cura 4.9, printed one-at-a-time, conditioned >=24 h at room temperature. TDS (file v5.00), April 29, 2022. |
Every value links to the document that states it. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.
Plastic TPU is 3D printed: its properties depend on build direction and print settings; these are typical values.
Questions
Is Plastic PEEK stronger than Plastic TPU?
Plastic PEEK is stronger: its yield strength is 98 MPa against tensile strength 23.7 MPa for Plastic TPU (4.14x).
Which is lighter, Plastic PEEK or Plastic TPU?
Plastic TPU is lighter: 1,220 kg/m³ against 1,300 kg/m³ for Plastic PEEK.
Which is stiffer, Plastic PEEK or Plastic TPU?
Plastic PEEK is stiffer: Young's modulus 4 GPa against 0.067 GPa for Plastic TPU, so the same part in Plastic PEEK deflects less under the same load.
Which is lighter for the same job, Plastic PEEK or Plastic TPU?
For the same stiffness or strength: Plastic PEEK is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie, strong beam, strong panel or plate.
| Part that must be | Plastic PEEK | Plastic TPU |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 56x heavier |
| Stiff beam (bending) | lighter | 7.25x heavier |
| Stiff panel or plate | lighter | 3.67x heavier |
| Strong rod or tie | lighter | 3.88x heavier |
| Strong beam | lighter | 2.42x heavier |
| Strong panel or plate | lighter | 1.91x heavier |
For the same stiffness or strength, mass scales with density over stiffness (or strength) raised to a power set by how the part is loaded: 1 for a rod in tension, 1/2 for a beam in bending, 1/3 for a panel (the standard material-selection indices).